The invention relates to an electro-optical modulator and to a method for generating such an electro-optical modulator.
Electro-optical modulators are employed especially for the generation of optical pulses in the field of high-speed data transmission. For example, electro-optic modulators in the form of Mach-Zehnder interferometers are used, these modulators comprising two optical waveguides as interferometer branches and an electrode arrangement for supplying a voltage across the optical waveguides in order to induce a phase shift of a light wave guided in the optical waveguides. For example, the electrode arrangement comprises a plurality of electrodes, wherein an individual driver unit for supplying a voltage across a segment of the optical waveguides is assigned to each one of the electrodes. Such a modulator is disclosed, for example, in the article “Low-Power Multi-level Modulation of InP MZM with In-line Centipede Structure Directly Driven by CMOS IC”, T. Yamase et al., Proceedings OptoElectronics and Communications Conference held jointly with 2013 International Conference on Photonics in Switching (OECC/PS), 2013.
The electrical data signal which is supplied to the optical waveguides of the modulator via the driver units for generating an optical output signal usually is converted using a digital-analog converter (which is e.g. a component of the driver unit) and/or is processed by a digital signal processor; in particular the frequency spectrum of the data signal fed to one of the driver units is modified in order to obtain an optical output signal with a predefined frequency spectrum. The signal processing is required in particular in order to be able to allocate the optical output signal to a provided frequency channel or a plurality of frequency channels.